Lamp-focusing apparatus



July 1, 1930. s. F. ARBUCKLE LAMP FOCUSING APPARATUS Filed Aug. 21.

INVENTOR Jam uel Z'Arbucklc ATTORNEY Patented July 1,. 1930 UNITED; STATES PATENT OFFICE SAMUEL F. ARIBUCKLE, OF HIGHLAND PARK, MICHIGAN, ASSIGNOR TO MONOGRAM LEN S CORPORATION, OF NEW YORK, N. Y., A CORPORATION OF DELAWARE LMIP-FOCUSING APPARATUS Application filed August 21, 1925. Serial No. 51,557.

This invention relates to lamp focusing apparatus. More particularly, the invention relates to focusing mechanism adapted for use in connection with head lamps for automobiles or similar automotive vehicles, whereby the filament of electric lamp is adjusted to give maximum lighting efficiency.

In my copending application Serial No. 13,681, filed March 7, 1925 I have shown mechanism for securing both axial and lateral adjustment of the filament of the electric light bulb positioned in the lamp, this latter adjustment being secured by means of a transversely movable plate operable from the rear face of the head lamp and axial adjustment secured by a screw having its head extending outwardly to the rear of said above mentioned plate and accessible from the exterior of the head lamp casing and connecting with the socket of the lamp bulb, said socket being movable. In general, the present invention is an improvement on the construction in the copending application referred to.

Among important objects of the present invention is the provision of adjusting means for the filament of an electric bulb positioned in a reflector which fixedly maintains its adjustment independently of disturbances aris ing from vibration of the support of the lamp. Another object of the-invention is the utilization of a simplified mechanism for adjusting the focal position of a light source in a reflector which is adjustable entirely from the exterior of the lamp casing. Another important object is a provision of simplified adjusting devices for a lamp bulb support through which the number of necessary movable parts is limited to a minimum number. Various other objects relating to means for completely closing of apertures in the rear wall of the casing through which adjustment is made, thereby preventing the ingress of dust and relating further to details of construction and methods of manufacture, will appear on consideration of the following,

specification and of the accompanying drawings, disclosing that Which may be a preferred embodiment of the invention in which Fig. 1 is a sectional elevation showing the adjusting mechanism.

F ig. 2 is a detail of the adjusting mecha nism taken along lines 22 of Fig. 1.

Fig. 8 is a detail showing holding means for the adjusting screw taken along lines 3-3 of Fig. 2.

Fig. 4 is a section taken along lines 1-4; of Fig. 1. 1

Fig. 5 is a detail showing the pin and slot attaching means for the lamp bulb base.

Referring to the drawings in detail, Fig. 1 discloses a head lamp of a type in use for automobiles having a casing 10, of cylindrical formation, having a base or rear wall 11, and an open front bounded by the angular flange 12. The open front is normally closed by means of a lens 13, circular in outline and having its periphery 14, of lesser thickness than the major portion of the lens, thereby forming a circumferential ledge 15, for a purpose presently to be described. Rim 16 is employed to hold the lens in position and afford means for opening and closing the casing. To this end the rim is pivoted by means of the interengaging hook members 17 and 18, and means are provided for maintaining the rim and attached lens in closed position about the periphery of the open side of the casing. The last mentioned means in the present invention consists of a bolt 20, mounted in a struck-in portion 21, of the rim 16, the head of the bolt being accessible from the exterior and the body of the bolt insertable in a nut 22, attached to the flange 12, of

the casing.

The reflector 25 of the lamp is positioned within the casing, facing the open side thereof. The reflector is preferably of parabolic cross-section and is centrally apertured as at 26, to receive the socket 27, for the head lamp bulb 28. The outer edge of the reflector is transversely extended to form rim 29, having an edge 29, adapted to engage and be secured as by welding operation or riveting to the flange 12 of the head lamp casing. As a cushioning means for the lens, which is normally positioned directly in front of the reflector, a channel, 30, is formed in the rim 28 of the reflector, in which a cord 31, is

placed, so that when the door rim 16 is in closed position, the lens, 13 is held against the cord 31, and is maintained from transverse movement through the engagement of a rearwardly directed edge portion 32 of the door rim about the ledge 15 of the lens, thus holding the members and maintaining the lens securely in position and preventing both transverse and axial movement thereof.

The lamp bulb employed in connection with the present invention is preferably of the two-filament type, the filament normally bein horizontal and equally disposed above and elow the axis of the reflector, the numerals 40 and 41 denoting the respective filaments. The lamp base 42 sets in a socket 27, and is held therein by means of the bayonet slot, the same being shown in detail in Fig. 5, this connection comprising a right angle slot 43, preferably notched on its forward transverse portion 44, and a pin 45, movable in said slot, the various notches 44 holding the pin yieldably in either one or a plurality of different positions.

For the double filament, two base contacts 46 and 47 are employed, these being normally in contact with the socket pins 48, there being spring means (not shown) for yieldably holding these pins 48 in contact with the lamp base terminals 46 and 47. The socket pins 48 are connected to externally projecting plugs 49, to which electric power is supplied by means of flexible connecting cords 50.

The socket 27 for the lamp bulb is slidable in the aperture 26, so that axial adjustment may be made of the position of the lamp bulb filaments, with reference to the reflector 25. The socket is also adapted to be pivoted through a limited angle on the walls of the aperture 26, and is also retained from rotation relative to the reflector by means of a plate 60, fixed to the casing wall and movable through notch 61, formed in continuation of the'wall of the aperture of the reflector, this notch being shown clearly in Fig. 4-,

The plate 60, preferably extends along the whole length of and beyond the rear end of the socket 27, and is formed with upwardly extending members 62 and 63, each of which is apertured and screw-threaded to receive the adjusting screw-threaded bolt 64. The bolt 64, mounted in the members 62 and 63 in screw-threaded engagement therewith, extends rearwardlyof the socket through an aperture 65 formed in the rear casing Wall 11, the bolt terminating in a head 66 of a sufficient diameter to cover aperture 65, and extended preferably beyond the limits of this aperture so that in case of lateral shifting of the bolt, the aperture is completely covered nevertheless.

Means for preventing accidental removal of the bolt 64 from the upstanding member 63 are provided in a cotter pin 67. Means for normally maintaining the member 62 with the attached socket at its forward limit with reference to the casing wall 11, are provided in a coil spring 68, one end of which contacts with the member 62 and the other end of which engages a washer 69 on the bolt 64 and adjacent casing wall 11. There is also provided means tending to restrain rotation of the adjusting bolt 64, this means comprising a spring plate 70 fastened at one end to the plate 60, as shown in Fig. 1, and free to move at its other end, the central portion of said plate being humped and slotted axially to receive a portion of the bolt 64 and frictionally engage the same.

. It should be observed that the casing wall surrounding the aperture 65 is outwardly turned to form a bearing flange 71, contacting against the base of the bolt head 66 and maintaining the same out of contact with the casing proper. This construction diminishes the frictional action of the screw and also tends to prevent wearing away of finished material with which the casing may be coated.

Suspended from the bolt 64 intermediate the washer 69 and the casing wall 11, is a plate 80, as shown in Fig. 1 and Fig. 2, the plate apertured to receive at one end the bolt 64, and at its other end slotted as at 81 to receive gear mechanism. This gear mechanism as utilized in the present invention, consists of a rack gear 82, formed on the side of the slot and a pinion 83 placed within the slot and in engagement with a rack gear, this pinion being mounted in an aperture 84 formed in the casing wall 11, in which it is maintained in position by a knurled head 85 on the outside of the casing, and a spring member 86 positioned on a pin extension 87 of the pinion 83 and having laterally and rearwardly extending arms 88, the ends of which contactwith the rear base of the casing wall 11, A cotter pin 89, in engagement with a washer 90, holds the plate flexibly in position on the .pin 87, and thus retains the pinion in proper position relative to the casing wall.

The mode of operation of the mechanism, as above described, will now be detailed.

To secure axial adjustment of the filaments of the lamp in the reflector with reference to the focal plane of the parabolical reflecting surface, the operator manipulates the head 66, of the adjusting bolt 64, thereby shifting the socket 27 with the attached lamp bulb 28 until the proper adjustment is secured.

To adjust the filaments further, with ref erence to the focal axis of the reflector after positioning the filaments in the focal plane, the adjusting screw head 85 is rotated, this rotation in accordance with the direction of movementcausing a bodily transverse shifting of the plate 80 with the attached axially ad usting bolt 64, which in turn imparts a pivotal movementof the socket 27 in the aperture 26 of the reflector, and a consequent 'ver tical transverse movement of the filaments of the lamp bulb. This latter adjustment is carried on until preferably, as in the case where a two filament lamp bulb is used, the individual filaments are equally spaced from the focal axis of the reflector. If in this latter adjustment the light centers of the filaments have been shifted out of the focal plane, a second adjustment of the bolt head 66 should again be made. Ordinarily the initial setting of the focusing and bolting screws is sufficient to secure proper centering of the filaments. Thus it is apparent that with a simple manipulation of the adjusting bolt heads '66 and 85, the filaments of the lamp bulb are brought into adjustment not only with relation to the axis but also, to the focal plane of the reflector.

Reference has been made to the use of the two filament lamp bulb as sucha lamp bulb has been found useful in providing an eifective type of illumination. It should :be .un-

. derstood, however, that the filament adjustingmechanism is applicable with equally advantageous results in the case of a single filament bulb in which use the filament of the bulb is ordinarily brought directly into the axis of the reflector,.and its focal plane where the reflector is of. the parabolic type. It should be understood, moreover, that the invention is useful not only with automobile head lamps, but for any type of lighting mechanism in which :a light source is positioned in a reflector and is subject to adjustment. Lamps for various purposes include such as are used for motor boats, indoor and outdoor illumination and search lights.

As a feature of the invention attention is directed to the notched or roughened edge 44; of the bayonet slot connection between the socket 27 and the lamp bulb base 42. For uses, such as for example in connection with reflectorshaving a plurality of vertically positioned and spaced parabolic strips, it is ,advantageous to position the filamentsof the lamp bulb in certain predetermined positions. For example, in connection with this special type of reflector,.above referred to, the plane of the filament shouldbe transverse with the plane of the parabolic reflecting strips. By means of the notched edge 44 above referred to,'the lamp socket may be sli htly rotated to secure accurate adjustment 0' the filament in relation to the reflector. This type of bayonet slot adjustment isalso valuable in conjunction with the two filament lamp bulb as illustrated anddescribedin the present application, since with this type of bulb it is desirable that-each filament be, positioned directly above the other to prevent :a distortion of the light pattern.

Note should be made of that characteristic ofthe rack and pinion adjusting means whereby gradual working of the parts out of adjustment is obviated. This result is due to the short leverage on the pinion which prevents rotation thereof through jar or vibration, A feature of the invention also is the utility of the screw head 66 which serves not only as an adjusting means but also as a covering for .the slot :65, protecting the casing interior from dust and improving the appearance of the lamp casing.

. It is proposed also not to limit the position of the socket of the lamp at the axis of the reflector, as any convenient point displaced from said axis may be used as necessity may arise. It is apparent that the aperture in the adjustable plate may be spaced any distance from the axis of the socket providing appropriate means to be used to connect the socket with the-screw which passes through the aperture in the plate.

The spring 68 intermediate the plate 69 and socket, serves the important function of maintaining the entire structure in position as well as to resist frictional-1y, rotation of the adjusting screw. 1

The lens 13, may be designed for the spec'ific type of reflector or lamp bulb used, but-in the present embodiment of my invention, I prefer to use. a lens having vertically ridged refraction flutes or prisms positioned in three zones, the .outer zones having ridges of equal depth and the inner zone having equal ridges of lesser depth than those of the outer zones. A lens of this :type is advantageous in cooperating with the reflector and the filaments of the lamp bulb to secure a maximum lighting efiiciency.

Various modifications of the invention may, of course, be made, diffe i g i d ai from the embodiment herein shown and described, such as come within the spirit of the invention,.andtherefore,I desire .to claim the invention broadly as well as specifically, in accordance with the claims hereto appended.

Having thus described myinvention, what Iclaim as new and desire to secure by Letters Patent is 1. In lamp focusing apparatus, the combi nation of a casing; a reflector within the ca s ing having an aperture formed on the axis thereof; a lamp bulb socket loosely mounted within said aperture, said'socket being adapted to support a lamp bulb within the reflector; means for shifting said socket axially in the reflector aperture; and means for tilting said lamp socket in a vertical plane, said last mentioned means including a plate operative l y connected to the lamp socket and having rack teeth formed therein; and a pinion in operative engagement with said rack teeth, said pinion beingmounted in the rear wall of said casing and having a slotted head on the outside of thecasing-connected to said pinion, whereby rotationof the head causes rotation of the pinion and vertical movement of said plate.

2. In lamp adjusting mechanism, the combination of a casing; a reflector positioned within the casing, said reflector having an aperture adjacent to the axis of the reflector; a lamp bulb socket which is mounted within said aperture; an axially adjusting screw in operative engagement with said socket; a movable plate positioned within the casing in juxtaposition with the aperture formed in the rear wall of the casing and in axial alignment with said adjusting screw, said plate being apertured to receive the adjusting screw and said adjusting screw having a head external to said plate whereby rotation of the screw is obtained; a rotatable pin mounted in an aperture formed in the rear wall of the casing, said pin having a head external to said casing by which the pin is rotated; a pinion mounted on said pin interiorly of the easi linearly extending rack teeth formed on said plate and adapted to operatively engage said pinion whereby rotation of the pinion causes vertical movement of the plate and tilting adjustment of said socket.

3. In lamp focusing apparatus, the combinationof a casing having a slot formed in the rear wall thereof; a reflector having an aperture formed in its axis, positioned within the casing; a lamp bulb socket loosely mounted in the reflector aperture; a late positioned within said casing and ad acent said rear wall slot; an adjusting screw extending through the plate with its head external thereto, and its shank in threaded engagement with said socket whereby rotation of the screw brings about axial movement of the socket; a pin rotatably mounted in an aperture formed in the rear casin wall and having an external adjusting hea a pinion fixed to the pin; a rack gear fixed to said plate and in operative engagement with the pinion, whereby rotation of the pinion causes vertical movement of said plate and tilting adjustment of said socket.

4. In lamp focusing apparatus, the combination of a casing having a slot formed in the rear wall thereof; a reflector having an aperture formed in its axis, positioned within the casing; a lamp bulb socket loosely mounted in the reflector aperture a plate positioned with ing said casing and adjacent said rear wall slot; an adjusting screw extending through the plate with its head external thereto and to said casing, and covering said casing aperture and its shank in threaded engagement with said socket, whereby rotation of the screw brings about axial movement of the socket; a pin rotatably mounted in an aperture formed in the rear casing wall and having an external adjusting head; a pinion fixed to the pin; a rack gear fixed to said plate and in operative engagement with the pinion,

-' whereby rotation of the pinion causes vertical movement of said plate and tilting pivotal movement of said socket.

5. In lamp focusing apparatus, the combination of a casing having a slot formed in the rear wall thereof; a reflector having an aperture formed in its axis, positioned within the casing; a lamp bulb socket loosely mounted in the reflector aperture; a plate positioned within said casing and adjacent said rear wall slot; an adjusting screw extending through the plate with its head external thereto and to said casing and covering said casing aperture, and its shank in threaded engagement with said socket where rotation of the screw brings about axial movement of the socket; a pin rotatably mounted in an aperture formed in the rear casing wall and having an external adjusting head; means for maintaining said pin head in contact with the casing wall; a pinion fixed to the pin; and a rack gear fixed to said plate and in operative engagement with the pinion, whereby rotation of the pinion causes vertical movement of said plate and tilting adjustment of said socket.

6. In a lamp focusing apparatus for electric lamps, the combination of a casing having a slot in the rear wall thereof; a reflector positioned within the casing and having a notched aperture in its base adjacent the refiector axis; a lamp bulb socket slidably and pivotally mounted in said reflector aperture; a guide plate fixed to the socket and movable in the notch of the reflector aperture; a plate positioned within the casing; a screw connection between said guide plate and casing plate; spring means to frictionally hold said casing plate against said casing; and means for shifting said casing plate and thereby tilting said screw connection, guide plate and socket.

7. In a lamp focusing apparatus for electric lamps, the combination of a casing having a slot in the rear wall thereof; a reflector positioned within the casing and having a notched aperture in its base adjacent the reflector axis; a lamp bulb socket slidably and pivotally mounted in said reflector aperture; a guide plate fixed to the socket and movable in the notch of the reflector aperture; a plate positioned within the casing; a screw connection between said guide plate and casing plate; spring means for frictionally holding said plate against said casing; and means for shifting said casing plate and thereby tilting said screw connection, guide plate and socket, said means comprising a pinion and rack gear.

spring means to hold said plate in frictional engagement with said casing; means including an adjusting screw extending through the plate and easing slot with its head external to the casing and its shank in threaded engagement with said socket whereby rotation of the screw of the socket brings about axial movement of the socket; and pinion and rack mechanism for shifting said plate.

9. In a lamp, the combination with a re-' fieotor of a lamp socket pivotally engaging said reflector and provided with a rearwardly extending shank, a screw passing through a slot in said casing and engaging said shank I to adjust the same axially of the reflector, a

slide inside said casing engaging said screw, and means operable from outside the casing for moving said slide to rock said socket on its pivot.

In testimony whereof, I afiix my signature.

SAMUEL F. ARBUCKLE.

CERTIFICATE OF CORRECTION.

Patent No. 1,768,655. Granted July 1, 1930, to

SAMUEL F. ARBUCKLE.

It is hereby certified that error' appears in the printed specification of the above numbered patent requiring correction as follows: Page 3, line 83, strike out the word "to; page 4, line 66, claim'4, for the word "tilting" read vertical; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 28th day of October, A. D. 1930.

M. J. Moore, (Seal) Acting Commissioner of Patents. 

